Clusteroluminescent Monosaccharide, Oligosaccharide, and Polysaccharide

The development of green polymers is of critical importance for environmental sustainability and biomedical applications. Saccharides, as abundant natural polymers, have been widely used in food, agriculture, medicine, and medical devices. This review systematically summarizes the unique photophysical properties of monosaccharides, oligosaccharides, and polysaccharides that exhibit pronounced clusteroluminescence (CL). The emission mechanism based on through-space conjugation (TSC) is discussed, and negative hyperconjugation is further introduced, using polyethylene glycol as a representative structure, as an important weak interaction that modulates the electronic structures of CL materials. In addition, several unresolved issues in current CL research, extending beyond saccharide systems, are highlighted. It is anticipated that this review will stimulate further development of CL-based green polymers by advancing mechanistic understanding and enabling emerging functional applications.